On the microscopic anatomy of the rete testis a scanning electron microscopic and light microscopic study

The microscopic anatomy of the transitional zone of the seminiferous tubules, the tubuli recti and the rete testis in adult rats was studied with histological serial sections, semithin sections and scanning electron microscopy. In paraffin section most transitional zones of the seminiferous tubules seemed to be obliterated by the modified Sertoli cells. Thinner plastic sections showed always a lumen, however. PAS--positive material, thought to represent masses of degenerating spermatozoa surrounded by Sertoli cell nuclei was found in 20% of transitional zones. About 80% of the tubuli recti had an initial widening which surrounded the bulging Sertoli cell bodies of the transitional zones. The intratunical rete consisted of five to seven intercommunicating channels, usually of small caliber. One wide communication was regularly present, however. The extratesticular rete was usually formed of two wide cavities. From their subdivisions the five to seven ductuli efferentes arose. The rete epithelium varied from very thin squamous to cuboidal and even columnar. The epithelial cells contained a flagellum surrounded by peripheral microvilli. Loose connective tissue was found under the epithelium of all parts of the rete.